Digital BW, The Print

A lot of that will depend on both the amount of OBA's (i.e. how much OBA's are being used to whiten the coating/paper)
and the whiteness of the base sheet. If the coating without OBA's is still very white, and the base sheet is very white,
any breakdown of the OBA's should not cause appreciable yellowing. We are developing coatings which are OBA free and
still very close in whiteness to the OBA containing coatings we have used in the past. IMO yellowing is caused more
often by a chemical reaction - the paper touching something acidic or otherwise chemically reacting with the coating. I
have seen prints which were not framed with acid-free materials which developed yellowing of the coating rather quickly.
OBA's do react adversely with dye molecules, but I have not seen any research where they have been shown to react
adversely with pigments.
Diana York mailto:diana@...
Hawk Mountain Papers toll free 888-807-2248
http://www.hawkmtnartpapers.com
100% Cotton Fine Art Digital Print and Photo Papers


----- Original Message ----- 
From: "luisvcool" <lvictoria@...>


Thanks John and Diana.

VFA is such a nice paper.  So since VFA has OBA's this means that it will "yellow" in
time?  Even if it's under glass?  That's disappointing.

Diana, what papers from Hawk Mountain have a D-max and a texture like Epson VFA?  
I use an Epson 2200 with Epson inks and I make color and B&W (with OPM/IJC) prints.

Thanks.

By the by, how can one procure samples of the papers?

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Diana York" <diana@h...> 
wrote:
> A lot of that will depend on both the amount of OBA's (i.e. how much OBA's are 
being used to whiten the coating/paper)
> and the whiteness of the base sheet. If the coating without OBA's is still very white, 
and the base sheet is very white,
> any breakdown of the OBA's should not cause appreciable yellowing. We are 
developing coatings which are OBA free and
> still very close in whiteness to the OBA containing coatings we have used in the 
past. IMO yellowing is caused more
> often by a chemical reaction - the paper touching something acidic or otherwise 
chemically reacting with the coating. I
> have seen prints which were not framed with acid-free materials which developed 
yellowing of the coating rather quickly.
> OBA's do react adversely with dye molecules, but I have not seen any research 
where they have been shown to react

> adversely with pigments.
> Diana York mailto:diana@h...
> Hawk Mountain Papers toll free 888-807-2248
> http://www.hawkmtnartpapers.com
> 100% Cotton Fine Art Digital Print and Photo Papers
> 
> 
> ----- Original Message ----- 
> From: "luisvcool" <lvictoria@t...>
> 
> 
> Thanks John and Diana.
> 
> VFA is such a nice paper.  So since VFA has OBA's this means that it will "yellow" in
> time?  Even if it's under glass?  That's disappointing.

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Diana York" <diana@h...> 
wrote:
> A lot of that will depend on both the amount of OBA's (i.e. how much OBA's are 
being used to whiten the coating/paper)
> and the whiteness of the base sheet. If the coating without OBA's is still very white, 
and the base sheet is very white,
> any breakdown of the OBA's should not cause appreciable yellowing. We are 
developing coatings which are OBA free and
> still very close in whiteness to the OBA containing coatings we have used in the 
past. IMO yellowing is caused more
> often by a chemical reaction - the paper touching something acidic or otherwise 
chemically reacting with the coating.

Isn't it possible that the degraded form of the OBA is itself yellowish? This could be a 
cause of eventual yellowing--even if the paper itself is reasonably white (before 
addition of an OBA).

Phil